A variety of inflatable sport balls, such as a soccer ball, football, and basketball, conventionally incorporate a layered structure that includes a casing, a restriction structure, and a bladder. The casing forms an exterior layer of the sport ball and is generally formed from a durable, wear-resistant material. In soccer balls and footballs, for example, the panels may be joined together along abutting edges (e.g., with stitching or adhesives). In basketballs, for example, the panels may be secured to the exterior surface of a rubber covering for the restriction structure and bladder. The restriction structure forms a middle layer of the sport ball and is positioned between the bladder and the casing to restrict expansion of the bladder. The bladder, which generally has an inflatable configuration, is located within the restriction structure to provide an inner layer of the sport ball. In order to facilitate inflation (i.e., with air), the bladder generally includes a valved opening that extends through each of the restriction structure and casing, thereby being accessible from an exterior of the sport ball.